1. Field of the Invention
The present invention relates to a drug delivery system and, more particularly, a drug delivery system for separately holding a drug and a solvent in containers and aseptically mixing them to administrate the resultant solution to a patient.
2. Description of the Prior Art
In medical facilities such as hospitals, dry drugs such as powdered drugs, freeze-dried drugs or solid medicines held in drug containers or vials have been used for intravenous drip infusion by dissolving them in a diluent such as distilled water, a physiological saline, glucose solution, a drug solution or other solvent.
To facilitate dissolving operations, various drug delivery systems have been proposed of the kind wherein a drug container, such as a vial containing a dry drug, and a flexible container containing a diluent are connected to each other in series and adapted to be communicated with each other by piercing edges of a double pointed hollow needle into respective rubber plugs of the two containers to allow the diluent to flow into the drug container, for example, as in JP-T-S61-501129, JP-A-H2-1277 and JP-A-S63-135642.
JP-T-S61-501129, which corresponds to U.S. Pat. No. 4,583,971, to Bacquet et al. discloses a closed drug delivery system using a flexible container having a liquid diluent therein, a capsule coupled to the flexible container, a drug vial having a drug therein adapted to be mixed with the diluent, said drug vial being supported in the capsule by a supporting means of the capsule, and a coupling means for coupling the capsule to the interior of the flexible container. In this system, the drug vial is communicated with the flexible container by a communicating means arranged in the coupling means, thus making it possible to aseptically mix the drug with the solvent.
JP-A-H2-1277, which corresponds to U.S. Pat. No. 4,936,841 to Aoki et al., discloses a container having comprising a flexible container containing a diluent, a capsule having a cylindrical connecting portion at its one end and being connected to a mouth portion of the flexible container at the connecting portion, a drug container held in the capsule, and a communicating member arranged in the capsule for communicating the flexible container with the drug container. In use, the communicating member first pierces the plug in the drug vial and then pierces the flexible container to communicate the closing film of the flexible container with the drug container. Since the flexible container is communicated with the drug container in the closed system, it is possible to aseptically mix the drug with the solvent.
JP-A-S63-135642 (utility model) discloses a drug delivery system using a solvent container containing a diluent therein, a drug container or vial containing a dry drug and arranged in series with the flexible container, and a double pointed hollow needle slidably supported by a ring removably arranged in the drug container, the hollow needle being adapted so that one end pieces a rubber stopper of the drug container and at the other end of the needle pierces a rubber plug of the flexible container to aseptically connect two containers just before use.
All the above drug delivery systems of the prior art may be used with various vials on the market. However, conventional delivery systems utilize a piercing hollow needle to connect the drug container with the solvent container, so that as the rubber plugs are cored by the hollow needle, small rubber pieces result which are liable to cause mixing of the resulting drug solution with foreign substances. Further, the drug delivery system of JP-T-S61-501129 requires a several different parts that makes it necessary to manually break a frangible member arranged between the drug container and the diluent container, thus making it troublesome to handle. In addition, incomplete fracture of the fracturable member delays the flow of solvent, extending the time required for dissolution of the drug.
The drug delivery system of JP-A-H2-1277 is free from contamination by foreign substances and is much improved in operating simplicity, as compared with that of JP-T-S61-501129. However, it also requires a complex arrangement of several different parts for connecting the vial with the solvent container.
In contrast therewith, the drug delivery system of JP-A- S63-135642 (utility model) uses a small number of parts and is relatively simple in operation. However, it is necessary to apply a large external force to the vial to communicate the vial with the liquid container. Thus, it is troublesome to handle. Also, there is a fear of leakage of the drug solution when removing the double pointed needle from the plugs.